I mean i cant test this thing at all no one sells a MAP SENSOR tester no more. Has anyone heard of these hanging but will not show a code in the computer i got a 87 Vulcan and i got a popping noise fromt eh engine it is backfiring. I know it is not the common things like plugs wires timing TFI or the Pickup i got good compression and a new coolent temp sensor all fluids full replaced the knock sensor and also cleaned and replced the upper and lower manifold gaskets and rebuilt the fuel injectors with a new fuel filter and air filter new PCV and an oil change i oly got the 02 Sensor and the MAP Sensor to replace im running out of ideas ANYone?